ISRO all set to offer desi GPS for mobile users from next year

CHENNAI: NOT deterred by the malfunctioning of one of the NavIC (Navigation with Indian Constellation) satellites, the Indian Space Research Organisation (ISRO) is getting set for commercial roll out of ‘desi’ GPS in the second quarter of next year.The crucial miniaturisation of chipsets that go into wireless devices such as cell phones and wifi receivers has been achieved by the ISRO. One of the important elements for NavIC is the user receivers. User receivers are dedicated for finding user position using NavIC satellite signals.

The Space Application Centre (SAC) is responsible for development of NavIC user receiver. The technology for this is already available with SAC in a larger form. For mass applications like vessel tracking, vehicle tracking etc a smaller factor, low power and low cost receiver was needed.

As per different applications two different kinds of hardwares are required – digital and RF (radio frequency) front end. “Our semiconductor laboratory (SCL) in Chandigarh has developed the digital hardware and tested it. Now, the RF front end hardware is expected to hit the markets next month,” said Tapan Misra, director of Ahmedabad-based SAC to the Express.

Initially ISRO invited the industry to design and develop the chipsets. However there was little interest shown because of high investment costs. “The market didn’t want to take the first step. So we took it on ourselves to do it. Our SCL has developed the digital chips and for manufacturing prototypes of RF Front End hardware, we gave the order to Tower Jazz, a US-based firm specialised in silicon germanium technology suited for increasing bandwidth. We are planning to set-up a fabrication facility with silicon germanium processing technology in SCL,” Misra said.

To a query whether using a US firm’s services would dent the NavIC branding being totally ‘desi’, Misra said intellectual property rights of the design were with ISRO. “It’s only a commercial order to Tower Jazz, which won’t even know what it is,” he clarified. ISRO chairman A S Kiran Kumar told Express that the replacement satellite for IRNSS-1A, which erred, would be launched in August. Meanwhile, both digital and RF platforms would be integrated into one device that would offer greater bandwidth and excel in low power digital circuit implementations.

Misra said the final version would be an 11-channel chipset (7 NavIC satellites and four GPS satellites) operating under dual frequency (S and L bands). This actually delivered higher accuracy than GPS.
“GPS is dependent on L band and atmospheric disturbances affected its performance. To assess the errors, atmospheric models are used which would go erratic. In our case, we measure the difference in delay of dual frequency (S and L bands) and can assess the actual delay. Therefore NavIC is not dependent on any model to find the frequency error and is more accurate than GPS. To be precise, NavIC will provide standard positioning service to all users with a position accuracy of 5 metres. The GPS on the other hand, has a position accuracy of 20-30 metres,” Mishra said.

Economic viability
India proved to the world how robust and cost-effective the indigenous technologies were with the success of Mangalyaan or Mars Mission. Likewise, NavIC is operational with just 7 satellites; while China’s regional system ‘Beidou’ is a constellation of 35 satellites! Each satellite costs about D150 crore while the PSLV-XL version rocket costs about D130 crore. The seven rockets would cost about S910 cr, way cheaper than other platforms